In order to assess the effects of ash formation on boiler tubes, it was common to insert a small tube through a hole in the combustor wall of the boiler. The main problem with such prior art devices was in the accurate assessment of ash formation on a boiler tube under conditions similar to the actual boiler tubes in a combustion unit. Prior art devices were not capable of long duration since the sootblowing operation of conventional combustion units would disturb the ash deposit on the sample probe.
In addition, the coupon and ash temperature could not be maintained outside the combustor in prior art devices.
It is therefore a general object of the present invention to provide an improved long duration ash probe.
Another object of the present invention is to provide an ash probe which is automatically retractable from the combustion unit during sootblowing operations of the combustion unit.
Still another object is to provide a long duration ash probe capable of monitoring and controlling the temperature of the coupon thereof.
These and other objects will be apparent to those skilled in the art.